Following concept applies for map naming on rEvolt:

FIRST PART: Three digits. Continents / regions will have a three-digit number; main regions will have multiples of 4, side regions will have numbers next to the aligned main region. 

SECOND PART: One digit. Outside maps will have a 1, indoor maps will have a 2, caves and dungeons will have a 3.

THIRD PART: One or Two digits. Unique numbering for every corresponding main / side region.

EXAMPLES (current naming):

000-x-xx Intro.

001-1 Artis outdoor.
001-2-xx Artis indoors.
001-3-x Artis sewers.

002-x-x UNUSED; could be Area between Artis and Esperia.

004-x-x UNUSED; could be Esperia.

005-x-x UNUSED; could be Noile-Volen.

008-1 Hurnscald main outdoor map.
008-1-x Woodland outdoors.
008-2-xx Woodland / Hurns indoors.
008-3-x Woodland caves.

009-1-x Swamp / GY outdoors.
009-2-x Swamp / GY indoors.
009-3-x Swamp / GY caves + dungeons.

010-x-x UNUSED; could be Ukar Mountain area.

012-1 Candor outdoors.
012-2-x Candor indoors.
012-3-x Candor cave.

016-x-x Nivalis.

017-x-x UNUSED; could be Barbarians or Blue Sages Area.

020-x-x Tulimshar.

024-x-x UNUSED; could be Halizarno.